US11522506B2 - Compact RFIC with stacked inductor and capacitor - Google Patents
Compact RFIC with stacked inductor and capacitor Download PDFInfo
- Publication number
- US11522506B2 US11522506B2 US16/778,547 US202016778547A US11522506B2 US 11522506 B2 US11522506 B2 US 11522506B2 US 202016778547 A US202016778547 A US 202016778547A US 11522506 B2 US11522506 B2 US 11522506B2
- Authority
- US
- United States
- Prior art keywords
- capacitor
- inductor
- circuit
- top plate
- center
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active, expires
Links
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
- H03F3/21—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only
- H03F3/213—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only in integrated circuits
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
- H01L28/20—Resistors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
- H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body
- H01L27/06—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a non-repetitive configuration
- H01L27/0611—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a non-repetitive configuration integrated circuits having a two-dimensional layout of components without a common active region
- H01L27/0617—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a non-repetitive configuration integrated circuits having a two-dimensional layout of components without a common active region comprising components of the field-effect type
- H01L27/0629—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being a semiconductor body including a plurality of individual components in a non-repetitive configuration integrated circuits having a two-dimensional layout of components without a common active region comprising components of the field-effect type in combination with diodes, or resistors, or capacitors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
- H01L28/10—Inductors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
- H01L28/40—Capacitors
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/02—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
- H03F1/0205—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers
- H03F1/0288—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers using a main and one or several auxiliary peaking amplifiers whereby the load is connected to the main amplifier using an impedance inverter, e.g. Doherty amplifiers
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/189—High frequency amplifiers, e.g. radio frequency amplifiers
- H03F3/19—High frequency amplifiers, e.g. radio frequency amplifiers with semiconductor devices only
- H03F3/195—High frequency amplifiers, e.g. radio frequency amplifiers with semiconductor devices only in integrated circuits
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
- H03F3/24—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers of transmitter output stages
- H03F3/245—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers of transmitter output stages with semiconductor devices only
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/68—Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F2200/00—Indexing scheme relating to amplifiers
- H03F2200/222—A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F2200/00—Indexing scheme relating to amplifiers
- H03F2200/451—Indexing scheme relating to amplifiers the amplifier being a radio frequency amplifier
Definitions
- RFIC radio frequency integrated circuit
- LC inductor and capacitor
- RFICs are widely used in various applications including high power applications. These RFICs may be used in conjunction with power amplifiers that operate at high frequencies (e.g., 1-2 GHz), and often such power amplifiers include resonant LC circuits. LC circuits that have high resonance frequencies f 0 can take up a large area of the RFIC in order to achieve the desired resonance frequency f 0 . The physically large L and C components tend to increase IC size, complicate signal routing, and require many vias extending through the semiconductor substrate of the IC (through-substrate vias). Whenever possible, it is beneficial to reduce the size of RFICs, and reducing the size of LC circuits would help reduce the size of RFICs, as a single RFIC may include many LC circuits.
- FIG. 1 illustrates a circuit diagram in schematic form of a two stage radio frequency integrated circuit (RFIC) power amplifier system
- FIG. 2 illustrates a layout diagram of a top view of the power amplifier of FIG. 1 implemented on a monolithic semiconductor die
- FIG. 3 illustrates a layout diagram of an embodiment of the power amplifier of FIG. 1 that uses embodiments of stacked LC circuits in order to reduce the size of the power amplifier;
- FIG. 4 illustrates an example layout of a conventional LC circuit like those found in FIG. 2 ;
- FIG. 5 illustrates an example layout of an embodiment of a stacked LC circuit like those found in FIG. 3 ;
- FIG. 6 illustrates a cross sectional perspective view of a stacked LC circuit
- FIG. 7 illustrates another perspective view of a stacked LC circuit
- FIG. 8 illustrates a closeup view of the stacked LC circuit of FIG. 7 ;
- FIG. 9 illustrates a top view of the current density of a stacked LC circuit
- FIG. 10 illustrates a top view of the current density of a conventional LC circuit
- FIG. 11 illustrates a side cross sectional view of the current density of the stacked LC circuit of FIG. 9 ;
- FIG. 12 illustrates a side cross sectional view of the current density of the conventional LC circuit of FIG. 10 ;
- FIG. 13 illustrates an embodiment of a stacked LC circuit with a capacitor having holes
- FIG. 14 illustrates one example embodiment of a larger system or module that employs two of the power amplifiers described above, in the form of a Doherty power amplifier module.
- the embodiments include an RFIC using one or more stacked inductor-capacitor (LC) structures that may enable a significant miniaturization of the RFIC die.
- LC inductor-capacitor
- an inductor (L) may be aligned over a capacitor (C) in such a way that the feed for the capacitor connects to an interior portion of the top plate of the capacitor (e.g., near the center of the top plate) allowing for a more uniform current distribution.
- the stacked LC structure may be realized in a current semiconductor process flow with relatively simple mask changes, while avoiding changes to the process flow.
- an LC circuit to provide a radio frequency (RF) “cold” point/node may occupy a large area due to the inductance and the capacitance needed to resonate at the center frequency of operation, f o , of the design (e.g., 1-2 gigahertz (GHz) designs).
- the implementation of an embodiment of a stacked LC circuit may significantly reduce the area of the aforementioned LC circuits used in typical RFIC designs.
- Some candidate circuits for such an implementation include bias line low Q inductor-shunt capacitor networks, frequency selective integrated circuits (FSICs) used for bifurcation, etc.
- the power amplifier 101 includes a first amplification device 114 (e.g., a pre-amplifier power transistor) that may include a first field effect transistor (FET), and a second amplification device 126 (e.g., a final-stage amplifier power transistor) that may include a second FET.
- Each FET 114 , 126 includes a gate terminal (or input terminal), a drain terminal (or output terminal), and a source terminal, which is electrically coupled to a ground node (e.g., on the bottom of the RFIC).
- each of the first and second amplification devices 114 and 126 are FETs in the present embodiment, in other embodiments encompassed herein other amplification devices may be employed including, for example, other types of transistor devices such as bipolar junction transistors (BJTs).
- BJTs bipolar junction transistors
- the FET terms “gate,” “drain,” and “source” are used herein, the use of such terms is not meant to limit embodiments only to those that utilize FETs for amplification devices 114 , 126 .
- the signal that is to be amplified by the power amplifier 101 is a radio frequency (RF) input signal that is supplied to the power amplifier at a RF input port 102 .
- RF radio frequency
- the input impedance matching and bias circuit modifies the RF input signal to generate a modified RF input signal that is communicated from the input matching and bias circuitry to the first input terminal 140 .
- the input impedance matching circuit may include an input capacitor 104 connected between the RF input port 102 and the and first input terminal 140 .
- the input impedance matching circuit may further include a series RLC (resistor-inductor-capacitor) circuit including resistor 106 , inductor 108 , and capacitor 110 , wherein the RLC circuit is connected between the first input terminal 140 and ground.
- a bias voltage V g1 112 may be applied to a node between the inductor 108 and the capacitor 110 to bias the input to the first amplification device 114 .
- the first amplification device 114 also includes a first output terminal 142 (e.g., drain terminal). By virtue of operation of the first amplification device 114 , the modified (impedance transformed) RF input signal received at the first input terminal 140 is amplified to generate a first amplified output signal that is output at the first output terminal 142 .
- the first output terminal 142 of the first amplification device 114 is coupled to an interstage impedance matching and bias circuit, which is coupled between that first output terminal 142 and a second input terminal 144 (gate terminal) of the second amplification device 126 .
- the interstage impedance matching and bias circuit modifies the first amplified output signal provided by the first amplification device 114 at the first output terminal 142 to generate an additional RF input signal that is communicated to the second input terminal 144 .
- the interstage impedance matching and bias circuit includes an inductor 116 and a capacitor 124 that are connected in series between the first output terminal 142 and the second input terminal 144 , with the inductor 116 connected between first output 142 and capacitor 124 .
- the interstage impedance matching circuit further includes an LC circuit with an inductor 118 connected to a node between inductor 116 and capacitor 124 , and a capacitor 122 connected between the inductor 118 and ground.
- a bias signal V dt 120 may be applied to a node between the inductor 116 and the capacitor 122 to bias the output of the first amplification device 114 .
- the interstage impedance matching and bias circuit further includes an RLC circuit with a resistor 128 connected to the second input 144 and an inductor 130 , wherein the inductor 130 is further connected to a capacitor 132 , which is further connect to ground.
- a bias signal V g2 134 may be applied to a node between the inductor 130 and the capacitor 132 to bias the input to the second amplification device 126 .
- that amplification device Upon the second amplification device 126 receiving the additional RF input signal, that amplification device further amplifies that signal and generates a second amplified output signal (i.e., an RF output signal), which is output at a second output terminal 146 (drain terminal) of the second amplification device 126 .
- the second output terminal 146 is directly coupled to (or itself forms) a RF output port 136 of the power amplifier 101 , and the RF output signal generated by the second amplification device 126 accordingly can be output from the power amplifier 101 at that output port.
- FIG. 2 a layout diagram is provided that shows a top view of the power amplifier 101 of FIG. 1 implemented on a monolithic semiconductor die in more detail to reveal additional components (or subcomponents) of the power amplifier as shown in FIG. 1 .
- the semiconductor die includes a base semiconductor substrate (e.g., silicon, gallium nitride, gallium arsenide, and so on) in which various doped regions are formed (e.g., drain and source regions), and a build-up structure over the base semiconductor substrate that includes a plurality of patterned conductive layers that are separated by a plurality of dielectric layers, where portions of the patterned conductive layers are electrically coupled using conductive vias.
- a base semiconductor substrate e.g., silicon, gallium nitride, gallium arsenide, and so on
- various doped regions e.g., drain and source regions
- a build-up structure over the base semiconductor substrate that includes a plurality of patterned conductive layers that are separated by a plurality
- the build-up structure may include patterned conductive layers designated as M 1 , M 2 , M 3 , M 4 , M 5 , and so on, where the lower numbered metal layers are physically closer to the base semiconductor substrate.
- FIG. 2 each of the circuit elements from FIG. 1 . are shown using a similar numbering scheme. That is circuit elements 104 , 106 , 108 , 110 , 114 , and 126 correspond to circuit elements 204 , 206 , 208 , 210 , 214 , and 226 in FIG. 2 . The same correspondence is present for the other circuit elements of FIG. 1 .
- the power amplifier 201 includes each of the first amplification device (FET) 214 , the second amplification device (FET) 226 , the input matching circuitry 204 , 206 , 208 , 210 , and the interstage matching circuitry 216 , 218 , 222 , 224 , 228 , 230 , 232 coupled in series with one another between the RF input port 202 and the RF output port 236 , in a manner corresponding to what is shown in FIG. 1 .
- RF input port 202 may be considered a conductive bonding pad (or simply “pad”, herein), and RF output port 236 may be considered a pad as well.
- the various pads may be exposed at the top surface of the die, and configured for attachment of wirebonds to provide electrical connections to exterior circuitry.
- the inductors 208 , 216 , 218 , 230 may be implemented as distributed “spiral” inductors formed from patterned portions of one or more conductive layers of the build-up structure over the base semiconductor substrate, where each inductor includes first and second ends (or terminals) and a conductive spiral structure between the first and second ends.
- Each of the inductors 208 , 216 , 218 , 230 may have an inductance value in a range of about 0.5 nanohenries (nH) to about 10 nH in an embodiment (e.g., in an embodiment in which the RFIC has a center frequency of operation of about 1 to 3.5 GHz), although the inductance values may be smaller or larger depending on frequency and power level, as well.
- capacitors 204 , 210 , 222 , 224 , 232 may be implemented as parallel plate capacitors with first and second plates formed from overlapping, substantially rectangular patterned portions of two or more conductive layers of the build-up structure over the base semiconductor substrate.
- a lower plate may be formed from one metal layer (e.g., M 4 ), and an upper metal plate may be formed from another metal layer (e.g., M 5 ), with dielectric material between the two plates.
- each capacitor may be electrically connected (e.g., to inductors 208 , 216 , 218 , 230 ) as described below, and the second plate of each capacitor may be electrically connected to a ground reference (e.g., at the bottom surface of power amplifier 201 ) with through-substrate vias.
- each of capacitors 204 , 210 , 222 , 224 , 232 may also be implemented as a metal-insulator-metal (MIM) capacitor, a metal oxide semiconductor (MOS) capacitor (or “MOS CAP”), or another type of capacitor.
- MIM metal-insulator-metal
- MOS metal oxide semiconductor
- the capacitors 204 , 210 , 222 , 224 , 232 may have capacitance values in a range of about 5 picofarads (pF) to about 35 pF, in an embodiment, although the capacitance values may be smaller or larger, as well.
- the input matching and bias circuit includes capacitor 204 connected between the RF input 202 and the gate of the first amplification device 214 . Further, the input matching and bias circuit includes the series RLC circuit including resistors 206 , inductors 208 , and capacitors 210 connected in series between the gate of the first amplification device 214 and the ground reference. Note, in the power amplifier IC 201 , that two instances of the RLC circuit are shown and connected in parallel. One instance is present on either side of the input to the first amplification device 214 , which is a conventional design used to implement such circuits as shown in FIG. 1 . It is noted that certain other elements in the power amplifier 214 are implemented in this same parallel manner.
- the interstate impedance matching and bias circuit is coupled between the output of the first amplification device 214 and the gate of the second amplification device 226 .
- the interstage impedance matching and bias circuit includes an inductor 216 and a capacitor 224 that are connected in series between the output of the first amplification device 214 and the input terminal of the second amplification device 226 , with the inductor 216 connected between the output of the first amplification device 214 and a node coupled to a first plate of capacitor 224 , and a second plate of capacitor 224 is connected to the input terminal of the second amplification device 226 .
- the interstage impedance matching and bias circuit further includes an LC circuit with an inductor 218 connected to the node between inductor 216 and capacitor 224 , and a capacitor 222 connected between the inductor 218 and ground. Also, the interstage impedance matching and circuit further includes an RLC circuit with a resistor 228 connected to the input of the second amplification device 226 and an inductor 230 , wherein the inductor 230 is further connected to a capacitor 232 , which is further connect to ground.
- the inductors 208 , 218 , 230 of the LC circuits are implemented in different areas of the build-up structure from the areas in which the capacitors 210 , 222 , 232 of the LC circuits are implemented.
- the inductors 208 , 218 , 230 and the capacitors 210 , 222 , 232 do not overlap each other, but instead are disposed in horizontally adjacent areas of the build-up structure.
- the LC and RLC circuits of the interstage impedance matching and bias circuit each have two parallel instances of the circuit as described above with respect to the RLC circuit of the input impedance matching and bias circuit.
- the output of the second amplification device 226 is connected to the RF output 236 .
- the RF output 236 may be a conductive bonding pad that is configured for the attachment of wirebonds to provide electrical connections to exterior circuitry.
- FIG. 3 is another layout diagram of an embodiment of the power amplifier 101 of FIG. 1 that uses stacked LC circuits in order to reduce the size of the power amplifier 301 .
- a series-connected capacitor and inductor are now configured in a stacked or overlapping arrangement, in the horizontal plane of the build-up structure (i.e., each LC circuit incudes a stacked LC).
- the inductors 308 , 318 , 330 and the capacitors 310 , 322 , 332 overlap each other, and LC pair is disposed in a single area of the build-up structure.
- the inductors 308 , 318 , and 330 are stacked respectively with capacitors 310 , 322 , and 332 .
- the power amplifier 301 largely is laid out like the power amplifier 201 of FIG. 2 where the elements have a similar numbering scheme as FIG. 1 (and FIG. 2 ).
- the stacked LC will now be further described.
- FIG. 4 illustrates an example layout of an LC circuit like those found in FIG. 2 . Also an equivalent circuit diagram is shown.
- the LC circuit includes capacitor 410 and inductor 408 .
- the capacitor 410 may be a MIM type or MOS type capacitor as described above.
- the capacitor 410 includes an upper plate and lower plate with a dielectric material in between.
- the lower plate may be connected to ground using through substrate vias (TSV) 464 .
- TSVs 464 are shown in a bar shape, but may be any other shape as well.
- the TSVs extend through a base semiconductor substrate (not shown here) to a conductive layer on the backside of the base semiconductor substrate.
- the top plate of the capacitor 410 is connected to a first terminal of the inductor 408 using a connector 470 .
- the connector 470 is an underpass connector in this example. That is, the connector 470 is formed in a metal layer below (e.g., closer to the base semiconductor substrate) the metal layer(s) that form the inductor 408 . The connector 470 is then connected to the first terminal 472 of the inductor 408 that is in the center of the inductor 408 using one or more vias between the different conductive layers. The connector 470 may also use a via to connect to the top plate of the capacitor 410 , if the connector 470 and the top plate are on different levels of the IC. As illustrated, the inductor 408 is a coil conductor as described above. A second terminal 474 of the inductor 408 is electrically coupled to other components of the RFIC, as described above.
- FIG. 5 illustrates an example layout of a stacked LC circuit like those found in FIG. 3 . Also an equivalent circuit diagram is shown.
- FIG. 6 illustrates a cross sectional perspective view of the stacked LC circuit
- FIG. 7 shows a perspective view of the stacked LC circuit
- FIG. 8 shows a closeup view of the stacked LC circuit.
- Stacked LC circuit 500 includes capacitor 510 and inductor 508 .
- the capacitor 510 may be a MIM type or MOS type capacitor as described above.
- the capacitor 510 includes an upper plate 560 and lower plate 562 with a dielectric material in between.
- the lower plate 562 may be connected to ground using through substrate vias (TSV) 564 .
- TSV through substrate vias
- the TSVs 564 are shown in a bar shape, but may be any other shape as well.
- the TSVs extend through a base semiconductor substrate 566 to a conductive layer 568 on the backside of the substrate 566 .
- the top plate 560 of the capacitor 510 is connected to a first terminal of the inductor 508 using a connector 570 .
- the inductor 508 has a coil structure, and the first terminal is present at the central region of the coil structure and a second terminal 574 at the outer edge of the coil structure.
- the connector 470 is physically coupled to an edge of the top plate of the capacitor 410 . As used herein, this is referred to as being “edge fed.” In contrast, in the LC circuit of FIGS. 3 , 5 , and 6 , the connector 570 is physically coupled to an interior portion of the top plate 560 of the capacitor 510 (i.e., a portion at least 10 percent of the width of the top plate 560 away from the edge). As used herein, this is referred to as being “center fed.”
- One issue that arises with the LC circuit of FIGS. 2 and 4 is that, during operation, the current in the capacitor 410 is concentrated along the edge of the capacitor 410 near where the connector 470 connects to the capacitor 410 .
- FIG. 9 illustrates a top view of the current density of the stacked LC circuit 900
- FIG. 11 illustrates a side cross sectional view of the current density of the stacked LC circuit 900
- FIG. 10 illustrates a top view of the current density of the conventional unstacked LC circuit 1000
- FIG. 10 illustrates a top view of the current density of the conventional unstacked LC circuit 1000
- FIG. 12 illustrates a side cross sectional view of the current density of the conventional unstacked LC circuit 1000 .
- the current density plots illustrate that the distribution of current in the capacitor (e.g., capacitor 510 ) of the center fed stacked LC circuit 900 is more uniform than the distribution of current in the capacitor (e.g., capacitor 410 ) of the edge fed unstacked LC circuit 1000 .
- the current density along the edge of the capacitor 1010 where the connector 1070 connects to the capacitor 1010 is much higher than elsewhere. This then leads to increased current density in the TSVs 1064 closer to the edge of the capacitor 1010 that is connected to the connector 1070 as shown in FIG. 12 .
- FIG. 10 illustrates a side cross sectional view of the current density of the conventional unstacked LC circuit 1000 .
- the current density plots illustrate that the distribution of current in the capacitor (e.g., capacitor 510 ) of the center fed stacked LC circuit 900 is more uniform than the distribution of current in the capacitor (e.g., capacitor
- the current density in the inductor 908 of the stacked LC circuit 900 is much more uniform than the current density of the inductor 1008 of the unstacked LC circuit. This may be due to at least two factors.
- the inductor 908 may be made from a relatively thick copper layer (e.g., about 8-12 microns thick, such as 10 microns thick), while the inductor 1008 is made from a relatively thin aluminum layer (e.g., about 3.6 microns thick).
- the thicker metal layer for inductor 908 decreases the current density.
- the difference in material properties of copper versus aluminum also affect the differences in current density.
- the lower current densities of the stacked LC circuit 900 results in various benefits.
- TSVs may be a source of failures in integrated circuits. Increased current densities can lead to increased TSV failures.
- the TSVs need to be designed with increased current handling capacity which increases the amount of material needed as well as cost or more TSVs are needed.
- the plates of the capacitors are designed to accommodate the maximum current density found in the capacitor. Because of the increased current density in the capacitor 1010 , the plates should be designed to accommodate the local current density peaks, which also increases the plate thickness (and thus the amount of material used) as well as the cost.
- the increased uniformity of the current density observed in the stacked LC circuit 900 during operation means that the metal layers may be designed for a reduced maximum current capability.
- the stacked LC circuit may be utilized in matching network sections that include a resistor placed in series with the LC combination to improve amplifier stability. It should be noted that the proximity of the inductor coil to the top plate of the capacitor may results in a non-negligible parasitic capacitance 540 (as shown in the equivalent circuit diagram of FIG. 5 ). This parasitic capacitance 540 may be accounted for in the overall design of the stacked LC circuit to compensate for the effects of this parasitic capacitance 540 .
- this parasitic capacitance my warrant the use of a coil with reduced inductance, when compared with the inductance of a coil in an unstacked LC circuit, (e.g., a 10 nH inductor in an unstacked LC circuit may become an 8 nH inductor in a stacked LC circuit).
- the stacked LC circuit may have increased overall resistance.
- the resistors (for example 306 , 328 in FIG. 3 ) may be reduced to manage gain and stability.
- the resistors may be completely replaced by the resistance in the stacked LC circuit. This may be done to obtain the same frequency response as when using a conventional RLC circuit.
- a designer may trade-off gain to reduce the RFIC die area. For example, 1 GHz RFIC designs may have ample gain to trade-off to reduce the layout area to meet smaller die area requirements.
- the various metal layers may be made of aluminum as is typical in CMOS processing.
- the inductor 408 may be made of aluminum.
- the inductor 508 may be made of aluminum or copper, because a copper process may be used after and on top of the CMOS processing used to form the capacitor 510 .
- various combinations of metals may be used for the various metal layers in any combination based upon the underlying manufacturing processes.
- the stacked LC circuit uses a connector 570 between the inductor 508 and capacitor 510 , that connects to the top plate of the capacitor 510 (see FIG. 5 ) instead of connecting at the edge of the capacitor 410 in the conventional LC circuit (see FIG. 4 ). This may improve the current density uniformity in the capacitor. It also may reduce the complexity of the connection 570 between the capacitor 510 and the inductor 508 , which may be implemented using a simple conductive via. In the conventional LC circuit 400 , this connector 470 includes a conductive trace that goes under the inductor 408 , along with conductive vias, which increases the complexity of the conventional unstacked LC circuit in comparison with an embodiment of a stacked LC circuit.
- the connector 570 connects to the capacitor 510 away from the capacitor edge (e.g., in a central region of the capacitor 510 ).
- This central region may be defined as an area centered about the center of the capacitor. This may be the central 20%, 30%, 40%, 50%, 60%, 70% or 80% of the capacitor.
- the stacked LC circuit 500 may have a complete or partial overlap between the areas of the inductor 508 and the capacitor 510 .
- the available overlap options depend upon the relative sizes of the inductor and the capacitor. For example, when the inductor area is smaller than the capacitor area, the inductor may be placed so that the complete area of the inductor overlaps the capacitor. In this case the precise location may be driven by placing the connector as near the center of the capacitor as possible or in a specified central location. In another embodiment, it may be desirable to have such an inductor only partially overlap the capacitor with the connector in a desired central area. This may be done to reduce the losses and parasitic capacitance or to achieve certain specific circuit characteristics at the expense of increased area.
- a percentage of the area of the inductor 508 that overlaps the capacitor 510 is at least 10%, at least 25%, at least 50%, at least 75%, or 100%.
- FIG. 13 illustrates a stacked LC circuit 1300 with a capacitor 1310 having holes 1380 in either or both of the top and/or bottom conductive plates of the capacitor 1310 .
- the holes 1380 are shown as being aligned with the corners of the inductor 1308 .
- the corners of the inductor 1308 may cause fringe effects by interacting with the capacitor 1310 , and accordingly holes 1380 in the capacitor 1310 that are aligned with corners of the inductor 1308 may reduce these fringe effects.
- the holes 1380 may also minimize parasitic capacitance between the inductor coil and the capacitor top plate.
- the holes 1380 also reduce the shunt capacitor value, which may lead to a smaller coil to tune the LC circuit 1300 .
- FIG. 14 it should be appreciated that power amplifiers such as the power amplifier 101 that employ one or more improved biasing circuit arrangements can be implemented in any of a variety of other circuits and systems. Indeed, any of a variety of different circuits and systems can employ RFICs with improved stacked LC circuits such as those described above, and the present disclosure should be understood to encompass numerous circuit arrangements including single stage power amplifiers and other types of circuits.
- FIG. 14 particularly illustrates one example embodiment of a larger system or module that employs two of the power amplifiers 101 described above, in the form of a Doherty power amplifier module 1400 .
- the module 1400 particularly includes a splitter 1402 , a first peak amplifier RFIC 1404 that can take the form of the power amplifier 101 , and a first carrier amplifier RFIC 1406 that can also take the form of the power amplifier 101 . Also, the module 1400 further includes a Doherty inverter 1408 coupled between the carrier amplifier RFIC 1406 and the peak amplifier RFIC 1404 , and a Doherty output transformer 1410 .
- the module 1400 includes an RF input terminal 1412 at which an RF signal can be received from another source.
- the RF input terminal 1412 is coupled to the splitter 1402 such that the power of the RF input signal is divided by the splitter.
- the splitter in turn is coupled to each of the peak and carrier amplifier RFICs 1404 and 1406 , by way of respective conductive links 1414 and 1416 , respectively, by which split portions of the RF input signal (or split portions of a modified version of that signal) are provided to each of the RFICs.
- the carrier amplifier RFIC 1406 also outputs a first amplified RF output signal to the Doherty inverter 1408 by way of a conductive link 1426 , and the Doherty inverter further communicates an RF output signal or a modified version of it via a conductive link 1436 to a combining node (not shown), which in this example is present at the output of the peak amplifier RFIC 1404 .
- the peak amplifier RFIC 1404 outputs a second amplified RF output signal, and the first and second (carrier and peak) amplified signals are combined at the combining node.
- the combined RF output signal at the combining node is provided via the conductive link 1438 to the Doherty output transformer 1410 , which then outputs an RF output signal by way of a conductive link 1440 to a module RF output port 1442 .
- capacitors illustrated herein have been shown as rectangular structures, but other shapes are possible. Also, the inductors are shown as rectangular coils, but other shapes may be used as well.
- LC circuits may consume about 25% of the total area of the RFIC, and this area grows with increased frequency. By stacking the inductors and capacitors in the LC circuits, this area may be reduced by as much as 50%.
- the area of the RFIC of FIG. 3 is about 16% less than the area of the RFIC of FIG. 2 due to the stacked LC circuits.
- the same RFIC area may be maintained, but utilizing less area for the LC circuits (e.g., using stacked LC circuits) means that more area is available for the power amplifiers and other components, which may leader to a higher power device with the same area.
- the embodiments of the stacked LC circuits allow for the centrally-located inductor terminal to be connected directly to the top plate of the capacitor. This has the advantage of fostering more uniform current density in the capacitor, and thus potentially thinner capacitor plates. Also, this enables the removal of an underpass connection between the capacitor and inductor and simplifies the connection between the inductor and capacitor.
- the embodiments of the stacked LC circuits also allow for reducing the resistance value of an associated resistor in an RLC circuit, or enabling the resistor to be eliminated altogether.
- an embodiment of the capacitor may have holes in the capacitor plates that may help to reduce fringe effects with the inductor as well as reducing the capacitance of the capacitor.
- the amount of overlap between inductors and capacitors may be chosen to balance the area savings with other circuit parameters. Also, the relative sizes of the inductor and capacitor may affect the amount of overlap.
- an integrated circuit including: a semiconductor die; a transistor device integrally formed in the semiconductor die and having input and output terminals; and an inductor-capacitor (LC) circuit coupled to one of the terminals of the transistor device, the LC circuit comprising: a capacitor integrally formed in the semiconductor die and having a top plate and a bottom plate; an inductor integrally formed in the semiconductor die and having a coil structure and a first terminal; and a connector configured to couple the first terminal of the inductor and an interior portion of the top plate of the first capacitor, wherein the inductor at least partially overlaps the capacitor.
- LC inductor-capacitor
- a power amplifier system in an integrated circuit, the system including: a first transistor device having a first input terminal and a first output terminal; a second transistor device having a second input terminal and a second output terminal; an input matching circuit coupled to the first input terminal of the first transistor, the input matching circuit including a first inductor-capacitor (LC) circuit; an interstage matching circuit coupled between the first output terminal of first transistor and the second input terminal of the second transistor, the interstage matching circuit including a second LC circuit; wherein the first and second LC circuits each include: a capacitor having a top plate and a bottom plate; an inductor having a coil structure; and a connector configured to couple the inductor and an interior portion of the top plate of the capacitor, wherein the inductor at least partially overlaps the capacitor.
- LC inductor-capacitor
- a power amplification system including: an RF input terminal; a peak amplifier RF integrated circuit coupled at least indirectly to the RF input terminal; a carrier amplifier RF integrated circuit coupled at least indirectly to the RF input terminal, wherein at least one of the peak amplifier RF integrated circuit and the carrier amplifier RF integrated circuit includes: a transistor device having input and output terminals; and an LC circuit coupled to one of the terminals of the transistor device, the LC circuit including: a capacitor having a top plate and a bottom plate; an inductor having a coil structure; and a connector configured to couple the first inductor and an interior portion of the top plate of the first capacitor, wherein the inductor at least partially overlaps the capacitor.
- node means any internal or external reference point, connection point, junction, signal line, conductive element, or the like, at which a given signal, logic level, voltage, data pattern, current, or quantity is present.
- two or more nodes may be realized by one physical element (and two or more signals can be multiplexed, modulated, or otherwise distinguished even though received or output at a common node).
Abstract
Description
Claims (16)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US16/778,547 US11522506B2 (en) | 2020-01-31 | 2020-01-31 | Compact RFIC with stacked inductor and capacitor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US16/778,547 US11522506B2 (en) | 2020-01-31 | 2020-01-31 | Compact RFIC with stacked inductor and capacitor |
Publications (2)
Publication Number | Publication Date |
---|---|
US20210242840A1 US20210242840A1 (en) | 2021-08-05 |
US11522506B2 true US11522506B2 (en) | 2022-12-06 |
Family
ID=77062892
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US16/778,547 Active 2041-04-09 US11522506B2 (en) | 2020-01-31 | 2020-01-31 | Compact RFIC with stacked inductor and capacitor |
Country Status (1)
Country | Link |
---|---|
US (1) | US11522506B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20230369204A1 (en) * | 2022-05-10 | 2023-11-16 | Infineon Technologies Ag | Active under shielding for coils and transformers |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6590473B1 (en) * | 1999-10-15 | 2003-07-08 | Samsung Electronics Co., Ltd. | Thin-film bandpass filter and manufacturing method thereof |
US8228123B2 (en) * | 2007-08-29 | 2012-07-24 | Nxp B.V. | Integrated Doherty amplifier |
US8354882B2 (en) * | 2008-07-09 | 2013-01-15 | St-Ericsson Sa | Doherty amplifier with input network optimized for MMIC |
US8829999B2 (en) * | 2010-05-20 | 2014-09-09 | Cree, Inc. | Low noise amplifiers including group III nitride based high electron mobility transistors |
US8836078B2 (en) | 2011-08-18 | 2014-09-16 | Taiwan Semiconductor Manufacturing Company, Ltd. | Vertically oriented inductor within interconnect structures and capacitor structure thereof |
US20150235933A1 (en) * | 2014-02-19 | 2015-08-20 | Freescale Semiconductor, Inc. | Semiconductor devices, semiconductor device packages, and packaging techniques for impedance matching and/or low frequency terminations |
US20180323765A1 (en) | 2017-05-03 | 2018-11-08 | Qualcomm Incorporated | Compact scalable on-chip inductor-capacitor (lc) resonator using conformally distributed capacitors |
-
2020
- 2020-01-31 US US16/778,547 patent/US11522506B2/en active Active
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6590473B1 (en) * | 1999-10-15 | 2003-07-08 | Samsung Electronics Co., Ltd. | Thin-film bandpass filter and manufacturing method thereof |
US8228123B2 (en) * | 2007-08-29 | 2012-07-24 | Nxp B.V. | Integrated Doherty amplifier |
US8354882B2 (en) * | 2008-07-09 | 2013-01-15 | St-Ericsson Sa | Doherty amplifier with input network optimized for MMIC |
US8829999B2 (en) * | 2010-05-20 | 2014-09-09 | Cree, Inc. | Low noise amplifiers including group III nitride based high electron mobility transistors |
US8836078B2 (en) | 2011-08-18 | 2014-09-16 | Taiwan Semiconductor Manufacturing Company, Ltd. | Vertically oriented inductor within interconnect structures and capacitor structure thereof |
US20150235933A1 (en) * | 2014-02-19 | 2015-08-20 | Freescale Semiconductor, Inc. | Semiconductor devices, semiconductor device packages, and packaging techniques for impedance matching and/or low frequency terminations |
US20180323765A1 (en) | 2017-05-03 | 2018-11-08 | Qualcomm Incorporated | Compact scalable on-chip inductor-capacitor (lc) resonator using conformally distributed capacitors |
Also Published As
Publication number | Publication date |
---|---|
US20210242840A1 (en) | 2021-08-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10637400B2 (en) | RF amplifier with conductor-less region underlying filter circuit inductor, and methods of manufacture thereof | |
EP3331161B1 (en) | Amplifier die with elongated side pads, and amplifier modules that incorporate such amplifier die | |
EP3337037B1 (en) | Doherty amplifiers and amplifier modules with shunt inductance circuits that affect transmission line length between carrier and peaking amplifier outputs | |
US9787254B2 (en) | Encapsulated semiconductor device package with heatsink opening, and methods of manufacture thereof | |
US9698749B2 (en) | Impedance matching device with coupled resonator structure | |
CN106470019B (en) | Radio frequency amplifier module and method of manufacturing the same | |
US9531328B2 (en) | Amplifiers with a short phase path, packaged RF devices for use therein, and methods of manufacture thereof | |
US10861806B2 (en) | Amplifiers and amplifier modules with ground plane height variation structures | |
US10381984B2 (en) | Amplifiers and amplifier modules with shunt inductance circuits that include high-Q capacitors | |
US7084708B2 (en) | High-frequency amplification device | |
US11349438B2 (en) | Power amplifier packages containing multi-path integrated passive devices | |
CN107005204B (en) | Output matching network with single combined series and parallel capacitor assembly | |
CN115769372A (en) | RF amplifier package | |
US11088661B2 (en) | Power amplifier devices containing inverted power transistor dies and methods for the fabrication thereof | |
CN112928999A (en) | Amplifier and manufacturing method thereof | |
EP3544178A1 (en) | Amplifier device with harmonic termination circuit | |
US11522506B2 (en) | Compact RFIC with stacked inductor and capacitor | |
US10566938B1 (en) | System and method for providing isolation of bias signal from RF signal in integrated circuit | |
CN112787629A (en) | Active balun circuit, power amplification circuit and module | |
US9350316B1 (en) | Wideband baluns and methods of their manufacture | |
US20220399856A1 (en) | Doherty amplifiers and amplifier modules with shunt inductor and capacitor circuit for improved carrier harmonic loading | |
US20230260935A1 (en) | Transistor with integrated passive components | |
EP4333055A1 (en) | Packaged power amplifier device | |
US20120132969A1 (en) | Compensation network for rf transistor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NXP B.V., NETHERLANDS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SHILIMKAR, VIKAS;KIM, KEVIN;SCHULTZ, JOSEPH GERARD;REEL/FRAME:051685/0829 Effective date: 20200130 |
|
FEPP | Fee payment procedure |
Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: APPLICATION DISPATCHED FROM PREEXAM, NOT YET DOCKETED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NON FINAL ACTION MAILED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT RECEIVED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT VERIFIED |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |